Generic sealing rings for dynamic contact seals are well known and seal off components which move relative to one another, such as for example pistons, which are adjustable translationally back and forth, with respect to corresponding bearings, for example cylinders.
Such sealing rings may have an internal or external sealing action and may be of single-acting or double-acting design. The advantage of such a sealing ring lies in the fact that it requires only a relatively small installation space.
In the case of the sealing rings known from the prior art, by means of a corresponding geometry on a sealing lip, a contact pressure profile is generated which increases with a certain gradient. The contact pressure gradient that results from this is in this case definitive of a lubricating film thickness that is conveyed out under the sealing ring. Here, the steeper said gradient, the thinner the lubricating film that is conveyed out. Here, the thickness of the lubricating film is self-evidently dependent not only on the seal geometry but also on the movement speed, and commonly amounts to a few nanometres. The lubricating film that is conveyed out is in this case not to be regarded as leakage, because a modern sealing ring is even capable of conveying said lubricating film back into a pressure space again counter to the pressure. The entire sealing system is thus sealed off to the outside. To be able to impart their sealing action, such sealing systems or such sealing rings require a preload, which is normally applied by means of elastic elements, for example elastomer rings. Owing to the preload and the resulting friction, however, wear occurs, which in the long-term leads to the sealing action of the sealing ring deteriorating.